This invention relates generally to an improved method of obtaining fully dense, carburized, powdered metal, low alloy steel parts, the most common of which are the powdered metal equivalents of AISI 4000 and 4600 wrought steel series and particularly those having sintered carbon levels in the range of 0.22% to 0.37% by weight. More specifically, this invention is related to the improved method of carburizing powdered metal briquetted preform during the sintering step, or alternatively successively thereafter, and precedent to the foregoing step. Prior to our invention such powdered metal low alloy steel parts were first brought from a sintered preform to full density by a forging operation such as shown in U.S. Pat. No. 3,772,935, owned by assignee of the present invention; and subsequently, carburized by methods conventional for wrought steels. Such conventional heat treat methods include both liquid and gas carburizing. Where gas carburizing is used, either a batch type or continuous furnace may be used. The parameters to be controlled to achieve carburization of a fully dense part of specific hardness, case depth and carbon gradient are generally well known, as described, for example, in Metals Handbook, Eighth Edition, Vol. 2, pp. 67-114, published by the American Society for Metals.